Automated external defibrillators (AEDs) are portable electronic devices that can be used to automatically diagnose and treat patients with particular cardiac problems. AEDs typically treat patients through defibrillation—a process that applies electrical therapy to a patient's heart—to stop cardiac arrhythmias. The defibrillation can allow the patient's heart to reestablish an effective rhythm.
AEDs can be used to treat a patient before the patient can be treated by a medical professional, such as emergency first responders. Because AEDs can be used before medical professionals arrive to treat the patient, many AEDs are designed to be simple to use by people that do not have professional medical training, though such people may receive some training in using AEDs in first aid training or cardiopulmonary resuscitation (CPR) training.
Many cardiac conditions that are treatable by AEDs can lead to death or serious injury (e.g., brain damage) within minutes of the onset of symptoms. The patient's chances for avoiding death or permanent injury increase as the time between the onset of symptoms and defibrillation treatment decreases. In some cases, the survival rate of patients suffering from cardiac arrhythmia decreases by about 10% for each minute the administration of treatment is delayed, and the survival rate of some patients can be less than 2% after about 10 minutes without treatment. It is to the patient's benefit that a user of an AED be able to set up the AED and initiate defibrillation as quickly as possible.